Abstract: An optical architecture for an infrared vision system for binoculars or a camera. This system includes a front afocal, a scanner, an optical device forming an image of the scene and a cooled detector with cold stop. This architecture has an aperture stop which is seperate from the cold stop thereby causing varaitons in the structure flux over the extent of the detector. These varations are corrected by a suitable shape of the cold stop which smooths out the photometric inefficiency over the extent of the detector and decreases the photometric inefficiency.

Abstract: An infrared telescope, an apparatus for the harmonizing of its input and output axes including an infrared camera enabling the observation of an infrared scene and delivering a video signal representing the infrared scene, the infrared camera having a sighting axis that constitutes the input axis; a display screen receiving the video signal and displaying the corresponding image in the visible frequency spectrum; a bispectral, visible and infrared collimator, collimating the image displayed on the display screen at infinity, the collimator having an optical axis that constitutes the output axis; an infrared source positioned in a predefined way with respect to the output axis and positioned so that its radiation is collimated at infinity by the collimator; an element the reflection of the radiation coming from the infrared source at output of the collimator towards the infrared camera, the element enabling the formation on the display screen of an image of the infrared source; a device to measure the shift be

Abstract: A bidirectional optical amplification system which includes an optical amplifier having an input and an output and configured to amplify wavelengths lying within a range of wavelengths and an optical coupling device. The optical coupling device includes a first port configured to receive a first optical wave in a first subrange of wavelengths lying within a range of wavelengths, a second port configured to receive a second optical wave in a second subrange of wavelengths lying within the range of wavelengths, an optical coupling output coupled to the input of the optical amplifier, and an optical coupling input coupled to the output of the optical amplifier.

Abstract: Disclosed is an analog to digital converter with several cascade-connected interpolation and selection circuits. The function of an interpolation circuit is to produce five pairs of output signals from three pairs of input signals and select three pairs from among the five pairs to apply them to the next stage. Each pair comprises two interpolation signals that vary symmetrically and monotonically as a function of the voltage Vin, the signals of one pair being equal when the voltage Vin is equal to a reference voltage associated with this pair. There are five reference voltage associated with the five pairs. Among these five reference voltages, the three reference voltages (and therefore also the three corresponding pairs of signals) that most closely surround the input voltage Vin are selected. The reference voltages are increasingly closer together as the operation progresses in the succession of cascade-connected stages.

Abstract: Process for acquiring fingerprints, characterized in that it comprises the following steps:coating, with the aid of an ink, the surfaces of the fingers of a hand whose prints are to acquired;pressing a pad (2) of flexible material against the said coated surfaces;pressing the pad against a recording support (3). According to this process, the print is therefore taken on an intermediate pad and subsequently transferred to a paper support.

Abstract: An optical system for presenting an image to a user. The system includes an image source and an optical channel transmitting the image to the user's eye. It also includes an illumination of the ocular fundus and an imaging of the illuminated ocular fundus, both using part of the optical channel. The system enables an analysis of the eye retina observing an image. It also enables depending on the eye position, an adaptation of the visual image presented. If the system is partially mounted in a headset, it enables the presentation of the image to a mobile user.

Abstract: A special purpose processor for data processing. A transformation is determined in order to represent the input and output data as multidimensional spaces. The transformation is represented by an input matrix and an output matrix. These matrices make it possible to program the selection of the input and output data in a systematic manner and to determine a processor structure which is especially adapted to such programming. The system simplifies the use of processors operating in parallel.

Abstract: A display panel having compensation using holographic birefringent films. Due to the natural birefringence of liquid crystals, contrast suffers when a liquid crystal cell is viewed at an oblique incident angle. Compensation devices made of birefringent media are used to correct this deficiency. The compensation devices include at least one film, the birefringence of which is induced by the recording of a volume hologram consisting of parallel fringes. The choice of the optical birefringent axes depends only on the orientation of the fringes so that it is easy to achieve compensation using uniaxial films which are inclined with respect to the plane of the film.

Abstract: The disclosure relates to a bispectral electromagnetic wave detector including at least one first and one second overlaid plane active detector elements separated by a common layer, said first and second detector elements being sensitive to the different wavelengths; a first means of connection connected in common to said first and second detector elements, a second means of connection connected to said first detector element, and a third means of connection connected to said second detector element; means for applying successively a control voltage to each means of connection; and means connected to said first means of connection to detect a photoconduction current each time a control voltage is applied. The invention is used in applications requiring detection of electromagnetic waves in two bands of different wavelengths.

Abstract: A two-dimensional driving apparatus including: a plurality of support wires for elastically supporting a movable mount; a first driving device connected to the movable mount by a first driving wire capable of being elastically deformed for linearly moving the movable mount in a first direction; and a second driving device connected to the movable mount by a second driving wire capable of being elastically deformed, and installed at the same height of the first driving device for linearly moving the movable mount in a second direction perpendicular to the first direction.

Abstract: A divergence measurement antenna for single-pulse radars comprises at least two radiant panels. With their beams having the same center of phase, they are oriented differently. A monotonic function of the angular divergence of a signal received by the antenna is obtained from the ratio of the power of the signal received by the first panel to its power received by the second panel. An even-parity function of the signal received is obtained by taking the sum of these two signals. Application to precise measurements of angular divergence.

Abstract: In order to carry out the on-site determining of the error of orientational adjustment of an electronic scanning antenna, this error being due to defects of manufacture of the radiating face of this antenna, radioelectric measurements are used during the qualification of this antenna. These measurements are made for several directions of the antenna beam, and the most likely components of the aiming error are selected.

Abstract: An image output by a camera can contain a fault such that the signal output by the camera is not constant for a uniform background. To correct this fault, the method involves memorizing, as a correction image, a destructured image of the scene to be observed; this destructured image is generated by calculating the means of the signals obtained when the selected scene is observed while the camera settings are simultaneously modified inconsistently; the correction image is then subtracted from the image formed by the signals output by the detector during real observation of the scene selected with correct camera settings. Application to all scanning cameras.

Abstract: A method for controlling the navigation of a towed linear acoustic antenna. Birds equipped with variable-incidence wings are fixed onto the antenna. Through a differential action, the wings allow the birds to be turned about the longitudinal axis of the antenna so that a hydrodynamic force oriented in any given direction about the longitudinal axis of the antenna is obtained. Power and control signals are transmitted between the antenna and the bird by rotary transformers. The bird is fixed to the antenna by a bore closed by a cover. The bird can be detached automatically as the antenna is raised so that the antenna can be wound freely onto a drum. This method allows the full control of the deformation, immersion and heading of the antenna.

Abstract: The process applies to the approximate calculation of the exponential mean of a string of numbers u.sub.n coded in a floating-point format used to convey certain bit rate information in ATM networks, each number being defined with the aid of an exponent e.sub.n and a mantissa m.sub.n by a relation of the form u.sub.n =2.sup.e n.(1+m.sub.n /512). It consists in approximating the exponential mean by the code value associated with the exponential mean of the code words U.sub.n =512.e.sub.n +m.sub.n.

Abstract: A process for modelling of ground clutter received by a radar, starting from a meshed numerical terrain model, including identifying cells from the meshed numerical terrain model which comprise elements having a height greater than a resolution of the model; determining, for relevant cells, an average height of the elements; sectioning the relevant cells into height-wise slices; and calculating power backscattered by each of the relevant cells by representing contents thereof with elementary reflectors distributed over an entire height thereof as a function of adjoining cells and a profile of terrain situated between the radar and a relevant cell.

Abstract: This array antenna with anti-jamming in reception for radioelectrical or ultrasound waves is provided with radiating elements fitted out individually or in groups with amplitude-controlled and phase-controlled passive or active modules enabling aiming at transmission as well as at reception by analog beam-forming. It possesses a reception anti-jamming circuit carrying out successively two reduced, adaptive computational beam-forming operations, one in elevation which is performed on a grouping, in horizontal alignments, of the reception signals of the radiating elements and working on the reception signals by modifying the settings of the controlled modules and the other in relative bearing, performed on a grouping, in vertical alignments, of the signals of the radiating elements that which it phase-shifts and adds up to form a reception channel for the total antenna.

Abstract: A composite magnetic material showing reduced losses and reduced permeability when it is subjected to a magnetic field at frequencies below approximately 100 MHz. It comprises magnetic particles in the form of wafers dispersed in a dielectric binder. The polycrystalline magnetic ceramic wafers are oriented so that their main faces are substantially parallel to the magnetic field.Application especially to cores of inductors or transformers.

Abstract: A method enabling a multiple sensor equalization in a radioelectrical receiver including a specified number of reception antennas, the method including the steps of estimating the transmission channel on each of the antennas; estimating the background noise component plus interference on each of the antennas on the basis of the estimation of the transmission channel; estimating the spatial correlation matrix referenced R.sub.b of the background noise component plus interferences from the received signal; computing a spatial-temporal filter formed for each discrete temporal element of the estimated multiple-sensor channel of a spatial filter; achieving a temporal filtering of the data elements on the different sensors by the spatial-temporal filter; and equalizing the signal at output of the spatial-temporal filter by one-dimensional equalization at a symbol rate deciding the symbols transmitted.

Abstract: Present-day single or multiple fractional phase-locked loop frequency synthesizers are not phase coherent for they use a digital accumulator modulo a number P with a variable increment K, whose state is a function of the history of the change in values that have been imposed on the increment. This lack of phase coherence rules out the use of these synthesizers in certain fields such as that of Doppler radars. A novel type of single or multiple fractional phase-locked loop frequency synthesizer that is coherent in phase is proposed herein. This type of synthesizer comprises one or more counters with an increment of one, having their rate set by the reference oscillator of the synthesizer and being used in phase memories to enable changes in the increment or increments following a change in the fractional division ratio at instants that are synchronous with the reference oscillator.